Antiperspirants and Alzheimer's Disease. Back in the 1960s, a few studies found high levels of aluminum in the brains of people with Alzheimer's disease. The research suddenly called into question the safety of everyday household items such as aluminum cans, antacids, and antiperspirants.
A harmonic drive apparatus comprises a circular spline which has internal spline teeth and which is rotatable around a rotational axis , a flexible cylindrical flexspline which is concentrically disposed within the circular spline and which has external spline teeth , the number of flexspline external teeth being less than the number of internal ...
In mechanics and physics, simple harmonic motion is a type of periodic motion where the restoring force is directly proportional to the displacement and acts in the direction opposite to that of displacement.imple harmonic motion is typified by the motion of a mass on a spring when it is subject to the linear elastic restoring force given by Hooke's Law. The motion is sinusoidal in time and demonstrates a single resonant frequency.